Currently in networks using the 3GPP (3rd Generation Partnership Project) standard, roaming footprint control is typically a two step process. Roaming is the condition when a user takes her mobile station outside her Home Public Mobile Network (HPMN) and attempts to use it. The HPMN is the network serviced by the network provider in which the user has her subscription. A Visited Public Mobile Network (VPMN) is the network into which the user has entered. Footprint control allows the VPMN to pick and choose, down to the access point level (using Access Point Names (APNs)), when and where a roaming user can receive service on the VPMN's network. The networks can be mobile (cellular) networks such as GSM (Global System for Mobile Communications), TDMA (Time Division Multiple Access), and CDMA (Code Division Multiple Access) networks.
The steps for the current footprint control include that the VPMN verifies that a roaming agreement exists between it and another network when a subscriber of the other network (i.e. the HPMN in this example) attempts to register in the VPMN. The user's HPMN grants or denies service access to the subscriber based upon her service agreement or contract.
In an example, Provider A acting as VPMN may have countrywide roaming agreement with Provider B, such that Provider A allows all roaming service requests from subscribers of Provider B to Provider B. Provider B is then responsible for granting or denying service for each individual roaming subscriber.
Further, Provider A may have roaming agreements with Provider C only in certain market(s). In this case, Provider A may deny roaming service requests from subscribers of Provider C whenever these attempts take place outside of the market where a roaming agreement exists. Similarly, whenever these attempts take place inside of the market where the roaming agreement exists, Provider A may proxy all roaming service requests for subscribers of Provider C to Provider C, who would be responsible for granting or denying service for each individual subscriber.
Additionally, the 3GPP standard provides a method for footprint control named Regional Restriction Zones. In this method the HPMN defines, configures and controls user restricted zones. The zone restriction information is provided to the VPMN by the HPMN when the HPMN provides the registration/attach information. The VPMN is then expected to enforce the zones requested by the HPMN. As it stands, a HPMN may only use one VPMN zone for the whole country, thus there is no regional control. On the VPMN side, there is no control over the regions. The VPMN only enforces whatever regional zones are defined, maintained and passed to it from the HPMN. Even if a HPMN divides the nation into smaller zones, the zones are typically not “small” enough. Thus, while the existing zones are somewhat effective, this scheme is restricted to large zones, in which some parts of the zone the user may have been able to receive service. Thus, the existing solution is over restrictive.
Hence a need exists to provide the VPMN with more granular control over the areas of its network where roaming is to be allowed on a roaming agreement basis